Apparatus and methods for reducing corrosion of joining composite workpieces

Patent metadata

Field	Value
Publication number	US-9808856-B2
Application number	US-201414496829-A
Country	US
Kind code	B2
Filing date	Sep 25, 2014
Priority date	Sep 25, 2014
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

The present disclosure relates a rivet body, including a rivet head and a rivet shank, composed of a different material than a mandrel used for insertion into a workpiece(s), the mandrel including a mandrel shaft and a mandrel cap. The rivet body receives the mandrel shaft, including the mandrel cap, through the rivet shank. The mandrel shaft is received by the installation tool, which rotates the rivet body, and the mandrel cap locally deforms workpieces(s) through friction riveting to install the rivet body. During the friction riveting, the fast-rotating rivet body is pushed into the workpiece(s) causing local deformation/melting where the mandrel cap contacts the workpiece(s). The mandrel cap creates a cavity which progresses through an upper surface and a lower surface of the workpiece(s).

First claim

What is claimed is:

1. An apparatus, for joining a first workpiece and a second workpiece, comprising:
a rivet body comprising (i) a rivet head having an upper surface and a lower surface, wherein the lower surface is opposite the upper surface and configured to be positioned near or in contact with an upper surface of the first workpiece when the apparatus is used to join the workpieces, and (ii) a rivet shank attached to the lower surface of the rivet head, wherein the rivet body is at least partially composed of a non-conductive material that eliminates electrochemical pathways between the rivet body and at least one of the first and second workpieces and the rivet body; and
a mandrel comprising (i) a mandrel shaft configured to be positioned within at least a portion of the rivet shank, and (ii) a mandrel cap positioned on a portion of the mandrel shaft that is in contact with the rivet shank, wherein the mandrel cap is composed of a cap material having a hardness greater than that of the first and the second workpieces, thereby allowing passage of the mandrel cap through the first and second workpieces.

2. The apparatus of claim 1 wherein the mandrel cap, when used for joining the workpieces, creates a cavity progressing in the workpieces extending from the upper surface of the first workpiece, past a lower surface of the first workpiece and an upper surface of the second workpiece, and to or beyond a lower surface of the second workpiece.

3. The apparatus of claim 1 wherein:
the rivet shank has a first diameter;
the mandrel shaft has a second diameter differing from the first diameter;
the rivet shank has a ridge extending from the rivet shank; and
the ridge is configured to interlock with one or both of the first workpiece and the second workpiece.

4. The apparatus of claim 3 wherein the ridge comprises a ridge material being the same or similar in composition to the non-conductive material of the rivet body.

5. The apparatus of claim 3 wherein the non-conductive material of the rivet body is a first non-conductive material and the ridge comprises a second non-conductive material differing from the first non-conductive material.

6. The apparatus of claim 1 further comprising a washer adjacent the lower portion of the rivet head and configured to contact the upper surface of the first workpiece when the apparatus is used to join the workpieces.

7. A system, for joining a first workpiece and a second workpiece, comprising:
a rivet body comprising (i) a rivet head having an upper surface and a lower surface, wherein the lower surface is opposite the upper surface and configured to be positioned near or in contact with an upper surface of the first workpiece when the rivet body is used to join the workpieces, and (ii) a rivet shank, attached to the lower surface of the rivet head, wherein the rivet body is at least partially composed of a non-conductive material that eliminates electrochemical pathways between the rivet body and at least one of the first and second workpieces and the rivet body; and
a mandrel comprising (i) a mandrel shaft configured to be positioned within at least a portion of the rivet shank and the rivet head, and (ii) a mandrel cap positioned on a portion of the mandrel shaft that is in contact with the rivet shank and the head, wherein the mandrel cap is composed of a cap material having a hardness greater than that of the first and the second workpieces, thereby allowing passage of the mandrel cap through the first and second workpieces.

8. The system of claim 7 wherein the mandrel cap, when used for joining the workpieces, creates a cavity in the workpieces extending from the upper surface of the first workpiece, past a lower surface of the first workpiece and an upper surface of the second workpiece, and to or beyond a lower surface of the second workpiece.

9. The system of claim 7 wherein:
the rivet shank has a first diameter;
the mandrel shaft has a second diameter differing from the first diameter;
the rivet shank has a ridge extending from the rivet shank; and
the ridge is configured to interlock with one or both of the first workpiece and the second workpiece.

10. The system of claim 9 wherein the ridge comprises a ridge material being the same or similar in composition to the non-conductive material of the rivet body.

11. The system of claim 9 wherein the non-conductive material of the rivet body is a first non-conductive material and wherein the ridge comprises a second non-conductive material differing from the first non-conductive material.

12. A method, for joining a first workpiece and a second workpiece, comprising:
positioning, near an upper surface of the first workpiece, a mandrel configured to be received through at least a portion of a rivet body,
the rivet body comprising a rivet shank, having a diameter, and a rivet head comprising an upper surface and a lower surface, the lower surface of the rivet head becoming located in the positioning near the upper surface of the first workpiece, wherein the rivet body is at least partially composed of a non-conductive material that eliminates electrochemical pathways between the rivet body and at least one of the first and second workpieces and the rivet body; and
the mandrel comprising a mandrel shaft and a mandrel cap that is positioned on a portion of the mandrel shaft in connection with the rivet shank, wherein the mandrel cap is composed of a cap material having a hardness greater than that of the first and the second workpieces, thereby allowing passage of the mandrel cap through the first and second workpieces; and

applying, to the upper surface of the rivet head, a torque such that the mandrel cap generates frictional heat at the upper surface of the first workpiece, the frictional heat deforming the upper surface of the first workpiece and creating a cavity extending into the first workpiece from the upper surface of the first workpiece.

13. The method of claim 12 wherein, in the applying, the friction heat generated causes the mandrel cap to create a cavity in the workpieces extending from the upper surface of the first workpiece, past a lower surface of the first workpiece and an upper surface of the second workpiece, and to or beyond a lower surface of the second workpiece.

14. The method of claim 13 wherein the rivet shank has a first circumference and the mandrel shaft further comprises a ridge about a second circumference, the second circumference of a different size than the first circumference, wherein the ridge is configured to interlock with the first workpiece or the second workpiece.

15. The method of claim 14 wherein the ridge is of a material similar in composition to the material of the rivet shank.

16. The method of claim 14 where the ridge is of a material different in composition from the material of the rivet shank.

17. The method of claim 13 wherein the rivet shank has a first circumference and the mandrel shaft further comprises a ridge about a second circumference, the second circumference of a different size than the first circumference, wherein the ridge is configured to interlock with the first workpiece and the second workpiece.

18. The method of claim 17 wherein the ridge is of a material similar in composition to the material of the rivet shank.

19. The method of claim 17 where the ridge is of a material different in composition from the material of the rivet shank.

20. The method of claim 12 further comprising a washer adjacent the lower portion of the rivet head and

Assignees

• Wang Pei-Chung
• Wang Chen-Shih
• Rousseau Ingrid A
• Gm Global Tech Operations Llc

Inventors

• Wang Pei-Chung
• Wang Chen-Shih
• Rousseau Ingrid A

Classifications

• F16B19/008

  with sealing means · CPC title

• F16B19/04

  Rivets; Spigots or the like fastened by riveting (lead seals G09F3/00) · CPC title

• B21J15/027 Primary

  Setting rivets by friction heating · CPC title

• B21J15/147

  Composite articles · CPC title